Water heater construction and sealing device therefor

ABSTRACT

A water heater construction including an inner tank for containing water surrounded in spaced apart relationship by an outer shell. An outer collar of insulation material is located in the annular space between the inner tank and outer shell at a preselected location within the annular space along the height of the water heater construction. The collar has a radial thickness greater than the radial width of the annular space and is radially compressed between the interior wall of the outer shell and exterior wall of the inner tank. An expandable foam thermal insulation material fills the annular space above the collar. A method of making the water heater construction includes the steps of positioning the collar of insulation material around and in contact with the interior wall surface of the outer shell and moving the outer shell downwardly concentrically over the inner tank displacing the inner perimeter margin of the collar at the interface of the collar and the water tank in a generally upward direction to form a trough in the collar at the top side of the collar.

BACKGROUND OF THE INVENTION

The present invention relates generally to hot water heaters and moreparticularly to a termally insulated water heater construction, asealing device therefor, and a method of manufacturing the water heater.

Typically, water heaters are formed of an inner water tank with an outershell located over the inner tank with an annular space therebetween.The space between the inner tank and outer shell is filled with athermal insulation. For many years fiberglass has been used as theinsulation material between the inner tank and outer shell. Morerecently, a foam such as urethane has been used as the thermalinsulation material in place of fiberglass between the inner tank andouter shell. Typically, foamable material is injected into the spacebetween the inner tank and outer shell, and is allowed to foam in situ.However, there is a problem in restraining the expanding foam within theannular space and more particularly within a predetermined location orregion with the annular space. This specific locational confinement ofthe foam is important when using such foam insulation in a gas-firedwater heater. In such an application it is extremely important to keepflammable foam away from the gas burner of the water heater. Over theyears various proposals have been made to solve this problem.

U.S. Pat. No. 4,372,028 issued to Clark on Feb. 8, 1983 shows a waterheater having a foam-filled closed collar located in the annular spacebetween the inner tank and outer shell at the bottom of the inner tank,and the annular space above the collar filled with expanded foam. Thecollar functions as a stop to the expanded foam in the annular spacethereabove. This patent further shows a method of manufacturing thewater heater which includes the steps of forming a flexible, expandableclosed elongated bag having a hole therein through which an expandablefoam can be injected into the bag. The bag is filled with a foammaterial which expands the bag to form a collar, but before the foammaterial has had sufficient time to fully expand, the bag opening issealed and the bag is circumferentially wrapped around the lower end ofthe tank with the bag ends overlapping each other. Next, and stillbefore the foam material in the collar has had sufficient time to fullyexpand, the outer shell is positioned over the inner tank and bag. Thefoam in the bag continues expanding forming a collar which is incompression between the inner tank and outer shell. The annular spaceabove the collar is then filled with expandable foam material.

U.S. Pat. No. 4,447,377 issued to Denton on May 8, 1977 shows agas-fired water heater wherein a layer of fiberglass insulation materialis wrapped around the bottom portion of the inner water tank around thecombustion chamber and a plastic envelope is wrapped around the innertank above the fiberglass insulation. The envelope is in the form of anelongated thin tube having an inner wall, an outer wall, a bottom wall,two end walls and an open top. When wrapped around the inner tank, theend walls of the envelope abut each other. The outer shell is positionedover the inner tank such that the envelope is in the annular spacetherebetween. Expandable foam is injected through the open envelope topinto the envelope and allowed to expand therein.

U.S. Pat. No. 4,477,399 issued to Tilton on Oct. 16, 1984 shows a waterheater having an inflatable toroidally shaped tube located around thebottom end of the inner tank such that when the toroidal tube isinflated with air, it seals the bottom end of the annular space betweenthe inner tank and outer shell. A foamable material is then injectedinto the annular space above the toroidal tube to fill the annularspace.

U.S. Pat. No. 4,875,272 issued to Nelson on Oct. 24, 1989 shows a waterheater construction having a wedge-shaped member disposed between theinner water tank and the outer shell wherein the apex of the wedge ispointed in a downward direction and the base of the triangular shapeopens upwardly into the annular clearance space between the tank andshell. This open base portion is designed so as to receive a portion ofthe liquid foam-in-place insulation which is used to insulate around thetank and between the shell such that as the material foams in place aforce is exerted on the sides of the wedge due to the expanding foamthereby increasing the degree of interference between the sides of thewedge and the tank and shell.

SUMMARY OF THE INVENTION

The present invention provides a water heater construction, a sealingdevice used in the water heater construction, and method ofmanufacturing a water heater construction which provides for easyassembly.

More particularly, the present invention provides a water heaterconstruction comprising an inner water tank, an outer shellconcentrically located over the inner water tank defining an annularspace therebetween, a collar of resilient material located in theannular space, the collar having a radial thickness greater than theradial width of the annular space, the collar having an annular troughformed in the top side of the collar, and the collar being radiallycompressed between the exterior wall surface of the water tank and theinterior wall surface of the outer shell.

The present invention also provides a sealing device for use in a waterheater construction in the annular space between a water tank andconcentrically disposed outer shell, the sealing device comprising acollar of resilient, flexible material to be concentrically locatedwithin the annular space having a radial thickness greater than theradial width of the annular space. A mechanical stop is provided forcontrolling the downward location of the collar relative to the watertank.

The present invention further provides a method for making a waterheater construction of the type having an inner water tank and an outershell concentric with and spaced from the inner water tank defining anannular space therebetween, comprising the steps of positioning a collarof resilient thermal insulation material around and in contact with theinside wall surface of the outer shell, the collar having a radialthickness greater than the radial width of the annular space, and movingthe outer shell downwardly coaxially over the full length of the watertank radially compressing the collar between the outer shell and innerwater tank in the annular space therebetween and displacing ordeflecting the inner perimeter margin of the collar at the interface ofthe collar and water tank in a generally upward direction to form atrough in the collar at the top side of the collar.

The present invention even further provides another method of making awater heater construction of the type having an inner water tank and anouter shell concentric with and spaced from the inner water tankdefining an annular space therebetween, comprising the steps ofpositioning a collar of resilient insulation material around and incontact with the perimeter of the inner water tank, the collar having aradial thickness greater than the radial width of the annular space, andmoving the water tank downwardly into the outer shell the full length ofthe outer shell radially compressing the collar between the outer shelland water tank in the annular space therebetween and displacing ordeflecting the outer perimeter margin of the collar at the interface ofthe collar and outer shell in a generally upward direction to form atrough in the collar at the top side of the collar.

BRIEF DESCRIPTION OF THE DRAWINGS

A better understanding of the present invention will be had uponreference to the following description in conjunction with theaccompanying drawings in which like numerals refer to like partsthroughout the several views.

FIG. 1 is a schematic representation, in transverse cross-section, of awater heater construction according to a typical embodiment of thepresent invention.

FIG. 2 is a schematic representation, in transverse cross-section, ofanother embodiment of a water heater construction according to thepresent invention.

FIG. 3 is a schematic representation, in transverse cross-section, ofyet another embodiment of a water heater construction according to thepresent invention.

FIG. 4 is a schematic representation, in transverse cross-section, ofyet a further embodiment of a water heater construction according to thepresent invention.

FIG. 5 is a schematic representation, in transverse cross-section, ofstill another embodiment of a water heater construction according to thepresent invention.

FIG. 6 is a schematic representation, in transverse cross-section, ofyet another embodiment of a water heater construction according to thepresent invention.

FIG. 7 is a schematic representation, in transverse cross-section, ofstill another embodiment of a water heater construction according to thepresent invention.

FIG. 8 is a schematic representation, in transverse cross-section, of afurther embodiment of water heater construction according to the presentinvention.

FIG. 9 is a schematic representation, in transverse cross-section, ofyet another embodiment of a water heater construction according to thepresent invention.

FIG. 10 is a schematic representation, in transverse cross-section, of afurther embodiment of a water heater construction according to thepresent invention.

FIG. 11 is a transverse cross-sectional view of a sealing collar deviceused in the water heater construction of the present invention.

FIG. 12 is a transverse cross-sectional view of another sealing collardevice used in the water heater construction of the present invention.

FIG. 13 is a transverse cross-sectional view of yet another sealingcollar device used in the water heater construction of the presentinvention.

FIG. 14 is a transverse cross-sectional view of still another sealingcollar device used in the water heater construction of the presentinvention.

FIG. 15 is a transverse cross-sectional view of yet a further sealingcollar device used in the water heater construction of the presentinvention.

FIG. 16 is a transverse cross-sectional view of still a further sealingcollar device used in the water heater construction of the presentinvention.

FIG. 17 is a transverse cross-sectional view of yet another sealingcollar device used in the water heater construction of the presentinvention.

FIG. 18 is a transverse cross-sectional view of still another sealingcollar device used in the water heater construction of the presentinvention.

FIG. 19 is a schematic representation, in transverse cross-section, of awater heater construction according to a typical embodiment of thepresent invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

For the purposes of promoting an understanding of the principles of theinvention, reference will now be made to the embodiment illustrated inthe drawings and specific language will be used to describe the same. Itwill nevertheless be understood that no limitation of the scope of theinvention is thereby intended, such alterations and furthermodifications in the illustrated device, and such further applicationsof the principles of the invention as illustrated therein beingcontemplated as would normally occur to one skilled in the art to whichthe invention relates.

FIGS. 1-10 schematically illustrate conventional type water heaterconstruction, generally denoted as the numeral 10, having an inner watertank 12 for containing water and an outer shell 14 concentricallysurrounding the inner water tank 12. The outer shell 14 and inner watertank 12 cooperate to define an annular space 16 therebetween. The waterheater device 10 is also shown as having a cap 18 and a floor 20 closingthe top end and bottom end of the annular space 16, respectively.

With continued reference to FIGS. 1-10, one of a variety of annularcollars 22a-22h of resilient insulation material is located in theannular space 16. The collar 22a-22h is fabricated of a nonflammableheat insulation material, for example, a fiberglass or foamed materialsuch as urethane, polyethylene, polystyrene, plastic, rubber and thelike. Hereinafter a general or generic reference to the collars will bedenoted by reference numeral 22. Specific reference to one of thevarious collar styles will be made by use of the letter suffix. Thissame approach will be followed for portions of each collar.

The collar 22 is located circumferentially within the annular space 16at a preselected location. In the preferred embodiment, the annularcollar 22 has a radial thickness greater than the radial width of theannular space 16 such that the collar 22 is radially compressed betweenthe exterior wall surface of the inner water tank 12 and the interiorwall surface of the outer shell 14 so that the outer circumferentialedge 24 of the collar 22 is compressed and partially flattened so as tobe in sealing contact with the interior wall surface of the outer shell16 and the inner circumferential edge 26 of the collar 22 is likewise ina slightly flattened condition and in sealing contact with the exteriorwall surface of the water tank 12. An annular trough 28 is defined atthe top side of the collar 22 with the opening of the trough facingupwardly toward the top of the water heater construction 10. The portionof the annular space 16 above the annular collar 22 is filled with anexpanded foam thermal insulation material 30 such as urethane,polyethylene, polystyrene and the like, which functions as thermalinsulation surrounding the inner water tank 12.

The trough 28 of the collar 22 in cooperation with the compression ofthe collar resist the pressure generated by the expanding foam material30 and prevent leakage past the collar 22 between the interface of theouter circumferential edge 24 of the collar 22 and the interior wallsurface of the outer shell 14 and between the interface of the innercircumferential edge 26 of the collar 22 and the exterior wall surfaceof the water tank 12. The risk of leakage is greatest when foamablematerial 30 is in its liquid state as it is being injected into theannular space 16 and is just beginning the process of foaming. Theportion of the annular space 16 beneath the collar 22 can be filled witha fibrous insulation 32.

With reference to FIGS. 1 and 11, the collar 22a has a generallyupwardly projecting annular lip 34a at the outside annular margin of thecollar 22a which cooperates with the top surface of the collar 22a todefine the annular trough 28a. The annular lip 34a is in abuttingjuxtaposition with the interior wall surface of the outer shell 14.

With reference to FIGS. 2 and 12, the collar 22b has a generallyupwardly projecting annular lip 36b at the inside annular margin of thecollar 22b which cooperates with the top surface of the collar 22b todefine the annular trough 28b. The annular lip 36b is in abuttingjuxtaposition with the exterior wall surface of the water tank 12.

Now with reference to FIGS. 3 and 13, the collar 22c has a generallyupwardly projecting annular lip 34c at the outside annular margin of thecollar 22c and another generally upwardly projecting annular lip 36c atthe inside annular margin of the collar 22c which cooperate with the topsurface of the collar 22c to define the annular trough 28c. The annularlip 34c is in abutting juxtaposition with the interior wall surface ofthe outer shell 14 and the annular lip 36c is in abutting relationshipwith the exterior wall surface of the water tank 12.

Now with reference to FIG. 14, the collar 22d has a transversecross-section generally in the shape of a trapezoid with the outercircumferential edge 24d of the collar 22d beveled outwardly toward thetop surface of the collar 22d when the collar 22d is relaxed beforeinstallation within the annular space 16. As can be seen in FIG. 4, whenthe collar 22d is installed in the water heater construction 10 withinthe annular space 16, the outer perimeter margin 38d of the outercircumferential edge 24d of the collar 22d is displaced in a generallyupward direction forming a lip 34d against the interior wall surface ofthe outer shell 14 which cooperates with the top surface of the collar22d to define the annular trough 28d.

Referring now to FIG. 15, the collar 22e has a transverse cross-sectiongenerally in the shape of a trapezoid with the inner circumferentialedge 26e of the collar 22e beveled outwardly toward the top surface ofthe collar 22e when the collar 22e is relaxed before installation withthe annular space 16. As can be seen in FIG. 5, when the collar 22e isinstalled in the water heater construction 10 within in the annularspace 16, the outer perimeter margin 40e of the inner circumferentialedge 26e is displaced in a generally upward direction forming a lip 36eagainst the exterior wall surface of the water tank 12 which cooperateswith the top surface of the collar 22e to define the annular trough 28e.

With reference to FIG. 16, the collar 22f is generally bowl-shaped intransverse cross-section with the outer circumferential edge 24f at ahigher elevation than the inner circumferential edge 26f when the collaris relaxed before installation within the annular space 16. As can beseen in FIG. 6, when the collar 22f is installed in the water heaterconstruction 10 within the annular space 16 the outer circumferentialedge 24f lays in overlaying juxtaposition with the interior wall surfaceof the outer shell 14 forming a lip 34f against the interior wallsurface of the water tank and defining the annular trough 28f.

With reference to FIG. 17, the collar 22g is a toroid generally squareor rectangular transverse cross-section shape with the outercircumferential edge 24g in the same plane as the inner circumferentialedge 26g when the collar is relaxed before installation within theannular space 16. Depending upon the various methods of assembly of thewater heater construction 10 to be discussed hereinbelow, the collar 22gwill assume somewhat different configurations within the space 16. Withreference to FIG. 7, the outer circumferential edge 24g is displaced ordeflected in a generally upward direction forming a lip 34g against theinterior wall surface of the outer shell 14 which cooperates with thetop surface of the collar 22g to define the annular trough 28g.Referring to FIG. 8, the inner circumferential edge 26g is displaced ordeflected in a generally upward direction forming a lip 36g against theexterior wall surface of the water tank 12 which cooperates with the topsurface of the collar 22g to define the annular trough 28g. Nowreferring to FIG. 9, the outer circumferential edge 24g is displaced ordeflected in a generally upward direction forming a lip 34g against theinterior wall surface of the outer shell 14 and the innercircumferential edge 26g is displaced or deflected in a generally upwarddirection forming a lip 36g against the exterior wall surface of thetank 12. The annular lip 34g and annular lip 36g cooperate with the topsurface of the collar 22g to define the annular trough 28g.

Now referring to FIG. 18, the collar 22h is a toroid with a generallycircular transverse cross-sectional shape when the collar 22h is relaxedbefore installation within the annular space 16. As can be best seen inFIG. 10, when the collar 22h is installed within the annular space 16,the outer circumferential edge 24h of the collar 22h is displaced in agenerally upward direction forming a lip 34h against the interior wallsurface of the outer shell 14 and the inner circumferential edge 26h ofthe collar 22h is displaced in a generally upward direction forming alip 36h against the exterior wall surface of the water tank 12. Lip 34hand lip 36h cooperate to define an annular trough 28h in the collar 22h.

With reference to FIGS. 11-18, the collar 22 can be constructed of avariety of materials. Referring for example to FIG. 11, collar 22a canbe fabricated of a fibrous insulation material 42, for examplefiberglass, enclosed in an impermeable envelope 44 of, for example,polyethylene film. With reference to FIG. 12, collar 22b can befabricated of a loose material 46, for example particles of foam,enclosed in an impermeable envelope 44 of, for example polyethylenefilm. With reference to FIGS. 13, 16, 17 and 18, the collar 22c, 22f,22g and 22h, respectively, can be fabricated of an expanded foammaterial 48, for example, a closed cell foam, or molded rubber, orflexible thermoplastic urethane which has an impermeable outer surfacetherefore eliminating the envelope 44. With reference to FIG. 14, thecollar 22d can be fabricated of, for example, an open cell expanded foammaterial 49. With reference to FIG. 15, the collar 22e can be fabricatedof an open cell expanded foam material 49 enclosed in an impermeableenvelope 44.

As shown in FIGS. 1, 2, 4, 6 and 7, the collar 22 can be attached to theexterior wall surface of the water tank 12 by, for example, an adhesiveor tape 50. Alternatively, as shown in FIGS. 3, 5 and 8, the collar 22can be attached to the interior wall surface of the outer shell 14 by,for example, an adhesive or tape 50. The collar can also be wedgedbetween the tank and shell without the use of tape as shown in FIGS. 9and 10.

The water heater construction 10 shown in FIGS. 1, 2, 4, 6 and 7 can beassembled by first positioning the collar 22 of thermal insulationmaterial around the exterior wall surface of the inner water tank 12with the inner circumferential edge 26 in contact with the exterior wallsurface of the water tank 12 at a preselected location therealong, andattaching the collar 22 thereto by using adhesive or tape 50. As shownin FIGS. 1, 4, 6 and 7, the collar 22 is located between the top end andbottom end of the water tank 12, but it should be understood that it canbe located any where along the water tank 12, for example, at the bottomend of the water tank as shown in FIG. 2. Next, the water tank islocated at the top end of and coaxial with the outer shell 14 and ismoved coaxially in a downward direction into the outer shell 14 the fulllength of the outer shell 14. Alternatively, the outer shell 14 ispositioned coaxially at the bottom end of the tank 12 and is movedcoaxially in an upward direction over the tank 12 the full length of thetank 12. The collar 22 is then radially compressed between the outershell 14 and inner water tank 12 in the annular space.

In the embodiments of FIGS. 1, 4, 6 and 7, the outer annular lip 34overlays the interior wall surface of the outer shell 12, and in theembodiment of FIG. 2, the inner annular lip 36 overlays the exteriorwall surface of the water tank 12. Next, expandable foam insulationmaterial 30 is placed in the annular space 16 above the annular collar22 filling the annular space 16 above the collar 22. In FIGS. 1, 4, 6and 7, the expanding foam 30 exerts a radial force against the outerannular lip 34 of the trough 28 of the collar 22 forcing the lip 34tightly against the interior wall surface of the outer shell 14increasing the sealing force at the interface of the collar 22 andinterior surface of the outer shell 14. In FIG. 2, the expanding foam 30exerts a radial force against the inner annular lip 36 of the trough 28of the collar forcing the lip 36 tightly against the exterior wallsurface of the water tank 12 increasing the sealing force at theinterface of the collar and exterior surface of the water tank 12. Withreference to FIGS. 1, 4, 6 and 7, a layer 32 of heat insulation materialcan be located in the annular space 16 beneath the collar 22.

The water heater constructions 10 shown in FIGS. 3, 5 and 8 can beassembled by first positioning the collar 22 of thermal insulationmaterial around the interior wall surface of the outer shell 14 with theouter circumferential edge 24 in contact with the interior wall surfaceof the outer shell 14 at a preselected location therealong, andattaching the collar 22 thereto by using adhesive or tape 50. As shownin FIG. 3, the collar 22 is located between the top end and bottom endof the shell 14, but it can be located at the bottom end of the shell 14as shown in FIGS. 5 and 8. Next, the outer shell 14 is located at thetop end of an coaxial with the water tank 12 and is moved coaxially in adownward direction over the full length of the water tank 12.Alternatively, the water tank 12 can be located at the bottom end of andcoaxial with the outer shell 14 and is moved coaxially in an upwarddirection into the shell 14 the full length of the shell 14. The collar22 is then radially compressed between the outer shell 14 and innerwater tank 12 in the annular space 16 with the annular lip 36 overlayingthe exterior wall surface of the water tank 12. Next, expandable foammaterial 30 is placed in the annular space 16 above the annular collar22 and is allowed to expand in situ filling the annular space 16 abovethe annular collar 22. With reference to FIG. 3, the expanding foam 30exerts a radial force against the outer annular lip 34 of the trough 28of the collar 22 forcing the lip 34 tightly against the interior wallsurface of the outer shell 14 increasing the sealing force at theinterface of the collar 22 and interior surface of the outer shell 14,and exerts a radial force against the inner annular lip 36 of the trough28 of the collar forcing the lip 36 tightly against the exterior wallsurface of the water tank 12 increasing the sealing force at theinterface of the collar 22 and exterior surface of the water tank 12.

With reference to FIGS. 5 and 8, the inner perimeter margin 40 of thecollar 22 is deflected or displaced in a generally upward direction tooverlay the exterior wall surface of the water tank forming lip 36 ofthe trough 28 at the top side of the collar 22. Expandable foaminsulation material 30 is placed in the annular space 16 above theannular collar 22 and is allowed to expand in situ filling the annularspace 16 above the annular collar 22. The expanding foam material 30exerts a radial force against the lip 36 formed by the upturnedperimeter margin 40 forcing the lip 36 tightly against the exterior wallsurface of the water heater 12 increasing the sealing force at theinterface of the collar 22 and exterior surface of the water heater 12.

The water heater constructions 10 shown in FIGS. 9 and 10 is assembledfirst by positioning the outer shell 14 concentrically over the innerwater tank 12 defining the annular space 16 therebetween. Next, theannular collar of FIGS. 17 or 18 is positioned at the top end of theassembly in alignment with the annular space 16 and is forced or pusheddownwardly into the annular space 16 to a desired position eitherbetween the top and bottom ends of the shell 14 or at the bottom end ofthe shell 14. The collar 22 is radially compressed between the outershell 14 and inner water tank 12 in the annular space 16. With referenceto FIG. 9 with the collar 22g of FIG. 17 the outer perimeter margin 38gis displaced or deflected in a generally upward direction forming anannular lip 34g against the interior wall surface of the outer shell 14and the inner perimeter margin 40g of the collar 22g is deflected ordisplaced in a generally upward direction forming an annular lip 36gagainst the exterior wall surface of the inner water tank 12 with anannular trough 28g defined between the lips 34g and 36g at the top ofthe collar 22g. With reference to FIG. 10, with the collar 22h of FIG.18, the outer perimeter margin 38h is distorted or displaced forming anannular lip 34h against the interior wall surface of the outer shell 14and the inner perimeter margin 40h of the collar 22h is distorted ordisplaced forming an annular lip 36h against the exterior wall surfaceof the water tank 12 with an annular trough 28h defined between the lips34h and 36h at the top of the collar 22h. In the embodiments of FIGS. 9and 10 expandable foam insulation material 30 is placed in the annularspace 16 above the annular collar 22 and is allowed to expand in situfilling the annular space 16 above the annular collar 22. The expandingfoam material exerts a radial force against the lip 34 forcing itagainst the interior wall surface of the shell 14 and a radial forceagainst the lip 36 forcing it against the exterior wall surface of thewater tank 12.

The water heater constructions 10 shown in FIGS. 1, 3, 4, 6, 7 and 10including the fiberglass insulation layer 32 beneath the collar 22 inthe annular space 16 is advantageously used when the water heaterconstruction 10 is gas-fired utilizing a combustion chamber at thebottom end of water tank 12. The collar 22 is positioned just above theelevation of the combustion chamber and the insulation layer 32surrounds the bottom end of the water tank at the combustion chamber.The water heater constructions 10 shown in FIGS. 2, 5, 8 and 9 isadvantageously used when the water heater is electronically heated anddoes not have a combustion chamber.

The tape member 50 serves a dual purpose and can be configured to workwith the assembly of collar 22 in a number of ways. When tape member 50is used to attach the collar to the tank (FIGS. 1, 2, 4, 6 and 7), it isthe tank which moves down into the shell or the shell which moves uparound the tank. Either way, the direction of relative motion allows theouter edge or lip of the corresponding collar to flex upwardly along theshell side wall thereby creating the aforementioned trough 28. As thisouter edge or lip flexes, the tape member holds the collar in positionagainst the tank. In certain configurations with certain collar styles,the amount of flexing is less and in some instances the trough iscreated in part by the starting shape of the collar. See, for example,FIG. 2.

When the reverse approach is used, i.e., the collar is attached to theshell, the direction of relative movement between the shell and tank isreversed such that the inside edge or lip of the collar flexes upwardlyalong the outer wall surface of the tank as is shown in FIGS. 5 and 8.FIG. 3 represents a situation where some flexing occurs, but thestarting shape of the collar is as much a factor in the creation of thetrough 28 as is any flexing of a lip or edge.

When the tape member is a rigid tape or adhesive member, such as anadhesive or tape covered piece of metal or plastic, other assemblytechniques are contemplated. One option is to use the member 50 as amechanical stop. While the concept of first assembling the shell andtank and then pushing the collar downwardly into the annular clearancespace is covered in FIGS. 9 and 10, member 50 can be first attached tothe shell or tank and used as a physical stop for the advancing collar.In this manner the desired location for the collar can be preset byattaching member 50 at the desired depth (or height) relative to eitherthe shell or tank. Since one arrangement for the tape or adhesive member50 includes covering it with a material that provides a tacky, adheringsurface, attachment of the member to either the shell or the tank isquickly and easily accomplished.

A still further option with regard to member 50 is to retain theL-shaped cross-section as shown in the various figures and use a tape oradhesive coating on the surface which attaches to the tank or shell. Theuse of tape or adhesive on the surface of member 50 which contacts thecollar is optional. If the collar is not to be bonded to member 50, thenthe collar merely rests on member 50 and the length of the horizontalportion extending radially between the tank and the shell becomes moreimportant. Further, in this arrangement, depending on the collar styleand where member 50 is attached, the direction of relative movementbetween the shell and tank may need to be reversed. For example, in theFIG. 1 arrangement, if the collar is merely resting atop member 50 andthe tank (and collar) move upwardly into the shell from the bottom edgeof the shell, the collar will tend to ride up and/or become twisted anddistorted. This can be avoided by lowering the shell down over the tankor by raising the tank upwardly into the shell. The downward force onthe outer edge of the collar is offset by the rigidity and supportoffered by tape member 50 such that the collar stays in position eventhough the movement of the tank into the shell tends to try and push thecollar down. One obvious change with this approach is that the outer lipor edge is not turned upwardly in order to create the desired trough 28and thus collar styles which are effectively formed with their owntrough such as collar 22a, 22b, 22c and 22f are more suitable with thisassembly approach.

A still further option is to use the tape member 50 as a rigid stopmounted to the tank, but place it on top of the collar as is illustratedin FIG. 19 which is virtually identical to FIG. 1 except for theposition of the member 50 relative to the collar. When member 50 ispositioned on the tank and placed above the collar, then the tank can bemoved downwardly into the shell or the shell upwardly around the tankand the outer edge or lip of the collar flexes upwardly in order tocreate trough 28. This can be done whether or not member 50 is flexibletape or a rigid tape member and whether or not the collar is adhesivelyattached to member 50. The same options are valid though in a reversedirection when member 50 is attached to the shell and positioned belowthe collar. Also note that the specific collar style is important inevaluating and employing all of the various options for member 50 andits positioning.

While the invention has been illustrated and described in detail in thedrawings and foregoing description, the same is to be considered asillustrative and not restrictive in character, it being understood thatonly the preferred embodiment has been shown and described and that allchanges and modifications that come within the spirit of the inventionare desired to be protected.

What is claimed is:
 1. A water heater construction comprising:an innerwater tank; an outer shell located in spaced relation to and surroundingsaid inner water tank so as to define an annular clearance space betweensaid inner water tank and said outer shell; a length of resilientinsulation material having a generally rectangular lateral cross-sectionand being formed into a movable annular collar and located within theannular clearance space, said movable annular collar having a free-stateradial width which is greater than the radial width of said annularclearance space and arranged in sealing contact with both the inner wallsurface of the outer shell and the outer wall surface of the inner watertank; stop means for establishing the position of said annular collar insaid annular clearance space; and said annular collar being movablerelative to said inner water tank and said outer shell through saidclearance space until abutment with said stop means.
 2. The water heaterconstruction of claim 1 wherein said stop means includes a tap membersecured to the inner water tank and disposed beneath said annularcollar.
 3. The water heater construction of claim 2 wherein said tapemember is rigid.
 4. The water heater construction of claim 1 whereinsaid stop means includes a tape member secured to the inner water tankand disposed above said annular collar.
 5. The water heater constructionof claim 1 wherein said stop means includes a tape member secured to theouter shell and disposed beneath said annular collar.
 6. The waterheater construction of claim 1 wherein said stop means includes a tapemember secured to the outer shell and disposed above said annularcollar.
 7. A water heater construction comprising:an inner water tank;an outer shell located in spaced relation to and surrounding said innerwater tank so as to define an annular clearance space between said innerwater tank and said outer shell; a length of resilient insulationmaterial having a generally circular lateral cross-section and beingformed into a movable annular collar and located within the annularclearance space, said movable annular collar having a free-state radialwidth which is greater than the radial width of said annular clearancespace and arranged in sealing contact with both the inner wall surfaceof the outer shell and the outer wall surface of the inner water tank;stop means for establishing the position of said annular collar in saidannular clearance space; and said annular collar being movable relativeto said inner water tank and said outer shell through said clearancespace until abutment with said stop means.
 8. The water heaterconstruction of claim 7 wherein said stop means includes a tape membersecured to the inner water tank and disposed beneath said annularcollar.
 9. The water heater construction of claim 8 wherein said tapemember is rigid.
 10. The water heater construction of claim 7 whereinsaid stop means includes a tape member secured to the inner water tankand disposed above said annular collar.
 11. The water heaterconstruction of claim 7 wherein said stop means includes a tape membersecured to the outer shell and disposed beneath said annular collar. 12.The water heater construction of claim 7 wherein said stop meansincludes a tape member secured to the outer shell and disposed abovesaid annular collar.
 13. A water heater construction comprising:an innerwater tank; an outer shell located in spaced relation to and surroundingsaid inner water tank so as to define an annular clearance space betweensaid inner water tank and said outer shell; a length of resilientinsulation material having a generally trapezoidal lateral cross-sectionand being formed into a movable annular collar and located within theannular clearance space, said movable annular collar having a free-stateradial width which is greater than the radial width of said annularclearance space and arranged in sealing contact with both the inner wallsurface of the outer shell and the outer wall surface of the inner watertank; stop means for establishing the position of said annular collar insaid annular clearance space; and said annular collar being movablerelative to said inner water tank and said outer shell through saidclearance space until abutment with said stop means.
 14. The waterheater construction of claim 13 wherein said stop means includes a tapemember secured to the inner water tank and disposed beneath said annularcollar.
 15. The water heater construction of claim 14 wherein said tapemember is rigid.
 16. The water heater construction of claim 13 whereinsaid stop means includes a tape member secured to the inner water tankand disposed above said annular collar.
 17. The water heaterconstruction of claim 13 wherein said stop means includes a tape membersecured to the outer shell and disposed beneath said annular collar. 18.The water heater construction of claim 13 wherein said stop meansincludes a tape member secured to the outer shell and disposed abovesaid annular collar.
 19. A method of making a water heater constructionhaving an inner water tank and an outer shell which is located in spacedrelation to and surrounding said inner water tank so as to define anannular clearance space between said inner water tank and said outershell, said method comprising the following steps:providing said innerwater tank; providing said outer shell; assembling stop means to one ofsaid inner water tank and outer shell so as to position said stop meanswithin said annular clearance space; placing said outer shell in spacedrelation to and around said inner water tank; providing a length ofresilient insulation material having a generally rectangular lateralcross section with a thickness greater than the radial width of saidannular clearance space; forming said length of resilient insulationmaterial into a movable annular collar such that said thicknessdimension becomes the radial width of said annular collar, said movableannular collar being movable relative to said inner water tank and saidouter shell through said clearance space; and pushing said annularcollar into said annular clearance space until abutment with said stopmeans.
 20. The method of claim 19 which further includes the step offoaming the annular clearance space above said annular collar with aliquid foam-in-place insulation.
 21. The method of claim 20 wherein saidstop member is attached to said inner water tank at the desired locationfor the lower edge of said annular collar.
 22. The method of claim 20wherein said stop member is attached to said outer shell at the desiredlocation for the lower edge of said annular collar.
 23. A method ofmaking a water heater construction having an inner water tank and anouter shell which is located in spaced relation to and surrounding saidinner water tank so as to define an annular clearance space between saidinner water tank and said outer shell, said method comprising thefollowing steps:providing said inner water tank; providing said outershell; assembling stop means to one of said inner water tank and outershell so as to position said stop means within said annular clearancespace; placing said outer shell in spaced relation to and around saidinner water tank; providing a length of resilient insulation materialhaving a generally circular lateral cross section with a diametergreater than the radial width of said annular clearance space; formingsaid length of resilient insulation material into a movable annularcollar such that said thickness dimension becomes the radial width ofsaid annular collar, said movable annular collar being movable relativeto said inner water tank and said outer shell through said clearancespace; and pushing said annular collar into said annular clearance spaceuntil abutment with said stop means.
 24. The method of claim 23 whichfurther includes the step of foaming the annular clearance space abovesaid annular collar with a liquid foam-in-place insulation.
 25. Themethod of claim 24 wherein said stop member is attached to said innerwater tank at the desired location for the lower edge of said annularcollar.
 26. The method of claim 24 wherein said stop member is attachedto said outer shell at the desired location for the lower edge of saidannular collar.
 27. A water heater construction comprising:an innerwater tank; an outer shell located in spaced relation to and surroundingsaid inner water tank so as to define an annular clearance space betweensaid inner water tank and said outer shell; a length of resilientinsulation material having a generally rectangular lateral cross sectionand being formed into a movable annular collar and located within theannular clearance space, said movable annular collar having an insidediameter surface and an outside diameter surface and having a radialwidth greater than the radial width of said annular clearance space anddisposed in sealing engagement against and between both the inner wallsurface of the outer shell and the outer wall surface of the inner watertank, said movable annular collar being forced into and moved throughsaid clearance space such that in its final assembled orientation, saidinside diameter surface deflects to form a lip which is compressedagainst the outer wall surface of the inner water tank and such thatsaid outside diameter surface deflects to form a lip which is compressedagainst the inner wall surface of the outer shell, the direction ofdeflection creating said lips is opposite to the direction of movementof said annular collar through said annular clearance space, whichfurther includes stop means positioned within said annular clearancespace for establishing the position of said movable collar, said movablecollar being positioned in abutment against said stop means.
 28. A waterheater construction comprising:an inner water tank; an outer shelllocated in spaced relation to and surrounding said inner water tank soas to define an annular clearance space between said inner water tankand said outer shell; a length of resilient insulation material having agenerally circular lateral cross section and being formed into a movableannular collar and located within the annular clearance space, saidmovable annular collar having an inside diameter surface and an outsidediameter surface and having a radial width greater than the radial widthof said annular clearance space and disposed in sealing engagementagainst and between both the inner wall surface of the outer shell andthe outer wall surface of the inner water tank, said movable annularcollar being forced into and moved through said clearance space suchthat in its final assembled orientation, said inside diameter surfacedeflects to form a lip which is compressed against the outer wallsurface of the inner water tank and such that said outside diametersurface deflects to form a lip which is compressed against the innerwall surface of the outer shell, the direction of deflection creatingsaid lips is opposite to the direction of movement of said annularcollar through said annular clearance space, which further includes stopmeans positioned within said annular clearance space for establishingthe position of said movable annular collar, said movable annular collarbeing positioned in abutment against said stop means.